Peel the eggs, and halve them lengthwise. Pop out the yolks, and transfer to a large dinner plate. Add 2 teaspoons water, and begin to mash with a fork. As you mash, add the mayonnaise, mustard, salt and pepper. Continue to mash until very smooth. Alternatively, use a food processor.
Carefully and slowly, use 2 teaspoons to fill each egg white cavity with the filling, distributed evenly among them. Lavishly sprinkle the topping all over the filled eggs, and serve cold or cool – plain, on toast, or on a salad.